tbuckley/cabot-search huggingface dataset:
Abstract 1088: Acquired radiation resistance induces thiol-dependent cisplatin cross-resistance
Authors: Samir V. Jenkins, Shruti Shah, Azemat Jamshidi-Parsian, Amir Mortazavi, Gunnar Boysen, Kieng B. Vang, Robert J. Griffin, Narasimhan Rajaram, Ruud P. Dings
Journal: Cancer Research (2023)

Abstract Purpose. Resistance to radiation, both intrinsic and acquired, remains a significant clinical challenge. It is therefore import to identify the underlying molecular and cellular features involved in this resistance. Materials and Methods. We generated genetically-matched counterparts of various degrees of radiation sensitivity in non-small cell lung carcinoma (NSCLC) tumor models to define characteristics of acquired resistance through repeated exposures to conventional X-ray radiation. Results. As assessed by cell viability and clonogenic assays murine Lewis lung carcinoma (LLC) and human A549 cell lines acquired an approximate 1.5 - 2-fold increase in radiation resistance (RR) as compared to its parental counterpart. Morphologically, we found that A549-RR exhibited a greater nucleus-to-cytosol (N/C) ratio as compared to its respective counterpart. Since the N/C ratio has been linked to the differentiation state, we next investigated the epithelial-to-mesenchymal transition (EMT) phenotype and cellular plasticity. We found that A549 have a greater radiation-induced plasticity, as measured by E-cadherin, vimentin and double positive (DP) modulation, as compared to LLC. Additionally, migration was suppressed in A549-RR, as compared to A549. Subsequently, we confirmed that the LLC-RR and A549-RR are also more resistant to radiotherapy than their isogenic-matched counterpart in vivo. Remarkably, we found that the acquired radiation resistance also induced resistance to first-line chemotherapeutic cisplatin, but not carboplatin or oxaliplatin. This cross-resistance was attributed to induced elevated thiol levels. Decreasing the amount of thiols with buthionine sulfoximine (BSO), a gamma-glutamylcysteine synthetase inhibitor, sensitized the resistant cells to cisplatin, to levels similar as parental cells. Conclusions. By generating genetically-matched radiation resistant NSCLC tumor models we were able to identify and overcome cisplatin cross-resistance. This is an important finding arguing for multi-modality treatment regimens with the potential of improving clinical outcomes in the future. Citation Format: Samir V. Jenkins, Shruti Shah, Azemat Jamshidi-Parsian, Amir Mortazavi, Gunnar Boysen, Kieng B. Vang, Robert J. Griffin, Narasimhan Rajaram, Ruud P. Dings. Acquired radiation resistance induces thiol-dependent cisplatin cross-resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1088.
Abstract 5292: Characterization of androgen receptor properties and interactome in mediating transcriptional condensates in prostate cancer
Authors: Nicholas C. Pinette, Shabnam Massah, Sofia Kochkina, Fan Zhang, Maitree Biswas, Joseph Lee, Jörg Gsponer, Nada Lallous
Journal: Cancer Research (2023)

Abstract In The United States of America 1 in 8 men will develop prostate cancer (PCa) in their lifetime. The assembly of phase-separated condensates containing players of the transcriptional machinery such as transcription factors, coactivators (e.g. MED1), and RNA polymerase II enhances the transcription of key oncogenes in various cancer including PCa. Many proteins undergoing phase-separation possess intrinsically disordered regions (IDR) that mediate multivalent intra- and inter-molecular interactions, essential for condensate formation. We recently demonstrated that full-length AR, the main oncogenic driver in PCa, is more prone to form nuclear transcriptional condensates upon androgen stimulation in PCa models than in benign epithelial prostate models. In this study, we investigated the effects of mutating or truncating key residues or regions involved in AR transcriptional activity on its ability to form nuclear condensates in LNCaP cells as visualized by confocal microscopy. We also used various bioinformatics tools to predict additional AR residues and sequences with high propensity for phase-separation. We thus made various truncations and mutations and evaluated their ability to form condensates in LNCaP cells. We also tested the effect MED1 phosphorylation and treatment with various inhibitors targeting different domains of the AR on the ability of full-length protein to form droplets in vitro. We hope by better understanding what drive AR condensates formation in PCa, to elucidate this new mechanism of transcriptional regulation and to identify new therapeutic avenues for patients with advanced forms of the disease. Citation Format: Nicholas C. Pinette, Shabnam Massah, Sofia Kochkina, Fan Zhang, Maitree Biswas, Joseph Lee, Jörg Gsponer, Nada Lallous. Characterization of androgen receptor properties and interactome in mediating transcriptional condensates in prostate cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5292.
Abstract 1375: Paranuclear retention of c-KIT by Merkel cell polyomavirus large T-antigen suppresses autophagy through interaction with Beclin 1 essential for Merkel cell carcinoma cell survival
Authors: Hao Shi, Yajie Yang, Catharina Larsson, Weng-Onn Lui
Journal: Cancer Research (2023)

Abstract Merkel cell carcinoma (MCC) is a very aggressive skin cancer most commonly caused by Merkel cell polyomavirus (MCPyV). While the strong expression of the human proto-oncogene c-KIT in MCC is well established, the functional relevance of this expression is unknown. Here, we demonstrate that paranuclear presence of c-KIT suppresses autophagy which is essential for maintenance of MCC cells. Specifically, after its phosphorylation, c-KIT traffics by clathrin-dependent endocytosis to late endosomes where it is sequestered in the paranuclear compartment by the MCPyV-encoded large transforming antigen (LT) via its Vam6p binding site, which also blocks c-KIT's lysosomal degradation. In this paranuclear compartment, c-KIT interacts directly with both the BH3 and the evolutionarily conserved domain (ECD) of Beclin 1, decreasing its binding to VPS34 and increasing its binding to BCL2, resulting in suppression of autophagy. Indeed, silencing of c-KIT induces autophagy and apoptosis in MCPyV-positive MCC cell lines. It is noteworthy that the positive feedback loop of LT and c-KIT also applies in the reverse direction, as LT is degraded via autophagy. This notion explains why an autophagy-inducing peptide efficiently induces apoptosis-independent cell death and inhibits tumor growth of MCC xenografts in mice. In conclusion, we identified a novel mechanism of MCPyV LT to suppress autophagy through sequestering and stabilizing c-KIT in the paranuclear compartment, which is mandatory to maintain the oncogenic phenotype of MCC cells. Autophagy-inducing agents therefore represent a therapeutic strategy for patients with advanced MCPyV-associated MCC. Citation Format: Hao Shi, Yajie Yang, Catharina Larsson, Weng-Onn Lui. Paranuclear retention of c-KIT by Merkel cell polyomavirus large T-antigen suppresses autophagy through interaction with Beclin 1 essential for Merkel cell carcinoma cell survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1375.
Abstract 5277: Activation of TRPM8 channel suppresses prostate cancer growth and progression
Authors: Swapna Asuthkar
Journal: Cancer Research (2023)

Abstract Prostate cancer (PC) is one of the most prevalent male malignancies and a leading cause of cancer-related deaths in men. While androgen-deprivation therapy is successful in the early stages of PC, tumor cells eventually become resistant to its effects. With a median survival of 18 months, the shift to androgen-independent prostate cancer (AIPC) has a poor prognosis. Mechanisms causing this change have yet to be explained, however mounting evidence implicates the loss of transient receptor potential melastatin 8 (TRPM8) as a significant contributor. The prostate epithelium normally expresses the ionotropic receptor TRPM8. Our team has recently shown that testosterone-induced activation of TRPM8 enhances Ca2+ absorption and causes apoptosis. This prompted us to propose that increased TRPM8 activity on the plasma membrane is cytotoxic to PC cells and that TRPM8 internalization is a crucial step in the pathogenesis of PC. We examined the amounts of TRPM8 mRNA in benign tumor and metastatic PC patient datasets. TRPM8 mRNA is initially elevated in the early stages of PC but is increasingly lost during the progression to AIPC. In addition, male and female TRPM8−/− mice exhibited increased serum testosterone levels, heightened AR activity, and activation of cell cycle, invasion, and adhesion-related effectors. In both AR+ and AR− xenograft models, our research reveals that TRPM8 possesses potent antitumor properties. Given this, investigating the in vivo role of TRPM8 in PC has the potential to significantly enhance patient outcomes by preventing progression to the androgen-independent state. Citation Format: Swapna Asuthkar. Activation of TRPM8 channel suppresses prostate cancer growth and progression. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5277.
Abstract 5562: Prevalence and prognostic significance of malnutrition in patients with brain metastasis
Authors: Zheran Liu, Yu Zhang, Yiyan Pei, Yan He, Jiayi Yu, Renjie Zhang, Jingjing Wang, Weelic Chong, Yang Hai, Xingchen Peng, Fang Fang
Journal: Cancer Research (2023)

Abstract Background: Malnutrition is a severe but modifiable risk factor for cancers. However, the relationship between malnutrition and the survival of patients with brain metastases has not been fully revealed. We aimed to evaluate the prevalence of malnutrition and assess its prognostic value on patients with brain metastases. Method: We retrospectively recruited 2633 patients with brain metastases between January 2014 and September 2020. Three malnutrition scores were used to evaluate patients' malnutrition status at their first admission, including controlling nutritional status (CONUT), the nutritional risk index (NRI), and the prognostic nutritional index (PNI). The association between malnutrition and overall survival was estimated. Results: A total of 1984 (75.4%) of patients were assessed as any degree malnourished and 963 (36.6%) of patients were assessed as moderate to severe malnutrition by at least one malnutrition score. The three malnutrition scores were associated with each other and with BMI. Malnutrition assessed by any of the three scores was significantly associated with poor overall survival (adjust hazard ratio [HR] and 95% confidence interval [CI] for CONUT: 1.12 [1.10-1.16]; for NRI: 0.97 [0.97-0.98]; for PNI: 0.96 [0.95-0.97], all p values &amp;lt;0.001). Furthermore, malnutrition was a better indicator than BMI, and adding malnutrition to the Graded Prognostic Assessment scoring system could significantly improve the accuracy of prognosis prediction. Conclusion: Malnutrition was prevalent in patients with brain metastases and was significantly associated with overall survival. Malnutrition monitoring on patients' first admission could improve the survival prediction ability for brain metastasis. Citation Format: Zheran Liu, Yu Zhang, Yiyan Pei, Yan He, Jiayi Yu, Renjie Zhang, Jingjing Wang, Weelic Chong, Yang Hai, Xingchen Peng, Fang Fang. Prevalence and prognostic significance of malnutrition in patients with brain metastasis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5562.
Abstract 5287: Is testosterone the male sex hormone responsible for increased male mortality in melanoma? <i>In-vitro</i> studies based on human melanoma (BLM) cell model
Authors: Pandurangan Ramaraj
Journal: Cancer Research (2023)

Abstract Clinical studies showed that menstruating females were better protected in melanoma than post-menopausal women and men of any age. But, these studies did not correlate with the steroid status of females. Our in-vitro study with progesterone (P), a female sex hormone showed significant inhibition of human melanoma cell growth. A literature survey showed that progesterone levels ranged between 1000-1500 ng/dl in menstruating females compared to post-menopausal women (20-100 ng/dl) and men (27-90 ng/dl), suggesting increased progesterone levels could offer protection to the menstruating females. Moreover, Elisarray showed that progesterone action was mediated by specific suppression of proinflammatory cytokine IL-8. So, it was proposed that a low level of progesterone in males leading to non-suppression of IL-8 in melanoma, could be responsible for increased melanoma cell growth and male mortality. This hypothesis prompted us to check the effect of male sex hormones androstenedione (AD) and testosterone (T) on melanoma cell growth and IL-8 secretion. Both AD and T decreased IL-8 secretion along with a decrease in cell growth. However, when progesterone was added along with androgens, there was a significant decrease in cell growth and in IL-8 secretion. This raised the question of why male mortality was high when androgens also decreased cell growth and IL-8 secretion. In order to address this question, it was decided to induce endogenous IL-8 in melanoma cells by pre-incubating with endothelin (50ng/ml) and then add steroids. AD and P individually decreased IL-8 secretion and in combination significantly decreased IL-8 secretion and cell growth even in endothelin pretreated cells when compared to their respective control cells. But, T was not able to suppress endogenous IL-8 induced by endothelin and in fact, cell growth also was slightly increased compared to straight T-treated cells. Conclusion: So, in males 2 reasons 1) a deficiency of progesterone and 2) inefficiency of T to suppress endogenous IL-8 could possibly result in increased IL-8 levels. This increased IL-8 level in males could lead to increased cell growth and metastasis in melanoma (IL-8 had already been shown to stimulate melanoma cell growth and metastasis by us and others) leading to death. So, a situation arising out of male reproductive endocrine physiology could probably be responsible for increased male mortality in melanoma. Citation Format: Pandurangan Ramaraj. Is testosterone the male sex hormone responsible for increased male mortality in melanoma? In-vitro studies based on human melanoma (BLM) cell model. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5287.
Abstract 3589: The use of a novel orthotopic xenograft model of fusion negative rhabdomyosarcoma to study the effect of ASAP1 on tumor progression and metastasis
Authors: Sarah M. Hammoudeh, Yeap Ng, Mukesh P. Yadav, Roberto Weigert, Paul A. Randazzo
Journal: Cancer Research (2023)

Abstract ASAP1 is a multidomain ADP-ribosylation factor (Arf) GTPase-activating protein (GAP) involved in the regulation of the actin cytoskeleton, focal adhesions dynamics and receptor tyrosine kinases trafficking. ASAP1 expression levels correlate with progression of solid tumors (e.g. breast, colorectal, pancreatic, ovarian, gastric, and prostate cancer). The first evidence for a role of ASAP1 in cancer progression was the discovery that the amplification of ASAP1 gene on chromosome 8 correlates with poor prognosis in uveal melanoma. A similar amplification of chromosome 8 has been reported in ~72% of fusion negative rhabdomyosarcoma (FN-RMS) tumors, suggesting a potential role for ASAP1 signaling in the progression of FN-RMS. To determine the function of ASAP1 in tumor growth, invasion and metastasis, we used a tongue orthotopic xenograft of FN-RMS which recapitulates physiologically relevant tumor progression and metastasis to lymph nodes and lungs, two of the common metastatic sites in patients. Using intravital microscopy, we observed that injected FN-RMS cells formed elongated structures and exhibited dynamic branching, which might represent local invasion. H&amp;E stained of fixed tissue revealed invasion into the tongue and local metastasis. Metastases to the regional lymph nodes, lower mandible and lungs were also observed. Using this system, we are now able to determine effect of knocking down and knocking out ASAP1 on the progression of the xenografts, including invasion in real time and metastasis. Citation Format: Sarah M. Hammoudeh, Yeap Ng, Mukesh P. Yadav, Roberto Weigert, Paul A. Randazzo. The use of a novel orthotopic xenograft model of fusion negative rhabdomyosarcoma to study the effect of ASAP1 on tumor progression and metastasis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3589.
Abstract 4398: Validation of an updated algorithm to identify non-small cell lung cancer (NSCLC) patients in administrative claims databases
Authors: Sandip Pravin Patel, Rongrong Wang, Summera Qiheng Zhou, Daniel Sheinson, Ann Johnson, Janet Lee
Journal: Cancer Research (2023)

Abstract Purpose: Administrative claims data using the ICD-9-CM or ICD-10-CM coding systems are not detailed enough to distinguish between lung cancer subtypes, which presents challenges for real-world research. This study updated and validated a previous treatment-based algorithm that uses claims data to identify NSCLC vs small-cell lung cancer (SCLC) (Turner RM, et al. Front Pharmacol 2017;8:883). Methods: This study used Optum’s de-identified Market Clarity Data (2007-2021) which deterministically links medical and pharmacy claims with electronic health record (EHR) data from providers across the continuum of care. Included patients had lung cancer diagnosis and histology information available in the EHR, which is the gold standard for validation. Patients were required to have ≥3 months of continuous health plan enrollment before and after the diagnosis date. First, to replicate the Turner algorithm, patients were identified between Jun 2014 and Oct 2015 with any first-line NSCLC treatment and no SCLC treatment (Step 1). Next, the Turner algorithm was applied from Nov 2015 to Dec 2020 to evaluate if performance decreased given the approval of immunotherapies since 2015 (Step 2). Finally, the Turner algorithm was updated with NSCLC treatments approved since 2015 in concordance with the latest US treatment guidelines. Algorithm performance at each step was measured using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results: Sample sizes and performance statistics for each step are presented in the Table. From Step 1 to Step 2, specificity and PPV decreased while sensitivity and NPV increased. Algorithm performance improved slightly for all measures from Step 2 to Step 3. Conclusions: This updated treatment-based algorithm improves validity and accuracy in identifying NSCLC patients in claims databases and supports its use in real-world research using claims databases when histology data is unavailable. Step 1: Turner replication Step 2: Turner 2015-2020 Step 3: Updated Turner 2015-2020 Date range Jun 2014-Oct 2015 Nov 2015-Dec 2020 Nov 2015-Dec 2020 Sample size 406 2573 2744 Sensitivity 0.873 0.920 0.932 Specificity 0.933 0.865 0.923 PPV 0.987 0.976 0.988 NPV 0.560 0.640 0.673 Citation Format: Sandip Pravin Patel, Rongrong Wang, Summera Qiheng Zhou, Daniel Sheinson, Ann Johnson, Janet Lee. Validation of an updated algorithm to identify non-small cell lung cancer (NSCLC) patients in administrative claims databases. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4398.
Abstract 5280: O-GlcNAcylation of progesterone receptor promotes mammary tumorigenesis
Authors: Harmony Ivanna Saunders, Sean M. Holloran, Gloria Trinca, Chad Slawson, Christy Hagan
Journal: Cancer Research (2023)

Abstract The role of hormone receptors in breast cancer has been well established as a key contributor to breast cancer tumorigenesis. Estrogen receptor and progesterone receptors are present in nearly 70% of breast cancers. The role of estrogen receptor and estrogens in breast cancer has been extensively studied and targeted effectively through endocrine therapy, however the impact of progesterone and the progesterone receptor (PR) independent of estrogen is not well understood. We have previously demonstrated that PR promotes tumor growth and drives an immune suppressive environment, therefore understanding the biology of PR in breast cancer is critical. We have also demonstrated that PR attenuates type 1 interferon signaling via inhibition of STAT1 phosphorylation and increased degradation of STAT2. Post-translational modifications such as phosphorylation and SUMOylation can influence PR target gene promoter selectivity thereby altering its function. Our recent work indicates PR is modified by O-GlcNAc, a single N-acetyl-glucosamine sugar that cycles on and off and serine or threonine amino acids in nuclear, cytoplasmic and mitochondrial proteins. Levels of total O-GlcNAc staining are higher in breast cancer tissue compared to adjacent normal tissue. Active O-GlcNAcylation, as evidenced by immunohistochemistry staining of O-GlcNAc-transferase (OGT), is elevated in patients with PR+ tumors compared to PR-. Using T47D breast cancer cells (an ER/PR-positive tumor line), mass spectrometry analysis revealed an O-GlcNAc site at S499 on PR. We then used a naturally occurring PR-negative variant of T47D cells to introduce stable expression of a mutant PR with serine to alanine substitution at the O-GlcNAc site (S499A), thereby blocking O-GlcNAc flux, in addition to wt PR as a control. RNA-Seq analysis of these cells following treatment with progesterone revealed several significant differential gene expression patterns, including rescue of PR dependent interferon signaling attenuation. T47D-mutant PR cell lines implanted into immune deficient mice had significantly decreased growth as compared to WT-PR control tumors. In syngeneic mice harboring PR-positive and PR-negative tumors, loss of O-GlcNAc flux and increased O-GlcNac levels increased tumor growth only when tumors were expressing PR, corroborating the influence of O-GlcNAc in immunodeficient mice. Together these findings indicate O-GlcNAcylation of PR is potentially a mechanism of PR driven breast cancer tumorigenesis and immune evasion. Citation Format: Harmony Ivanna Saunders, Sean M. Holloran, Gloria Trinca, Chad Slawson, Christy Hagan. O-GlcNAcylation of progesterone receptor promotes mammary tumorigenesis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5280.